1. Field of the Invention
This invention relates to attachments for roof panels, and more specifically, to an anchor mountable to a roof panel rib, to which roof paraphernalia may be attached, and the unique setscrew that secures to the roof panel rib.
2. Prior Art
Metal roof panels are in common usage. With such usage, it is often an advantage to attach equipment to the roof panel. For example, snow guards that control snow and ice sliding on the roof, cable guy wires, walking platforms, piping, signage, brackets, etc. It is important that such attachments not penetrate the roof panel so leaks are not introduced.
Metal roof panels are commonly joined with a raised portion on a first side overlapping a raised portion of an adjacent panel, together forming a roof panel rib raised above the general roof panels. In addition, some metal roof panels have an intermediate rib between the overlapping adjacent panel ribs. The panels are installed with the roof panel ribs running with the roof pitch, so an attachment anchor clamped on the rib can be positioned essentially anywhere on the roof, either laterally by choosing an appropriate rib and vertically along the pitch.
Because the attached paraphernalia may constitute a significant load on the anchor, such as a large sign or a snowfall collection, the anchor attachment must be able to sustain such loads without sliding on or disengaging from the roof panel rib. To prevent sliding and still not penetrate the roof panel, the anchor should have a friction or clamping attachment to the roof panel rib to allow the anchor to support the required loads. To achieve an attachment that can sustain loads of many hundreds of pounds, the anchor is clamped to the rib with a comparable force. To prevent disengagement from the roof panel rib, preferably the anchor should have structural features interconnecting with panel rib structural features that prevent lift-off regardless of friction.
A thin-walled roof panel rib is typically unable to sustain the clamping force required to keep the anchor from sliding on the roof panel rib without permanently deforming the roof panel rib. Once deformed, the roof panel rib is unable to readily come apart or go back together for roof panel replacement. The deformation disrupts the mechanism of the panel rib and is aesthetically displeasing. It is therefore also an advantage to have an anchor securable to a thin-walled metal roof panel at a roof panel rib without significantly deforming the roof panel rib or disrupting the panel interlock with the adjacent metal panel.